Peptide derivatives of exendin-4

ABSTRACT

In the current invention peptides, which are derived from GLP-1 (glucagon-like peptide-1) and exendin-3 and/or exendin-4, are provided which bond to the GLP-1 receptor and can be used, labeled or unlabeled, for the production of an agent for diagnostic and therapy of benign and malignant diseases, in which GLP-1 receptor expression plays a role.

The invention at hand concerns a method for the production of apharmacon for the depiction and therapy of primarilygastroenteropancreatic tumors, but also other benign and malignantdiseases of different organ systems, based upon the incretin hormoneGLP-1 and the analogs thereof.

DESCRIPTION AND INTRODUCTION OF THE GENERAL FIELD OF THE INVENTION

In the localization of gastroenteropancreatic neuroendocrine tumors,somatostatin receptor scintigraphy (SRS) is the most importantdiagnostic method next to ultrasound. The principle here is the specificdepiction of tumors with the help of radioactively labeled peptides,which are absorbed by the tumor cells. Then, with the help of gammacameras, the accumulation of the radioactivity in the tumor tissue canbe verified visually. When a type of tumor possesses one of thenecessary receptors for SRS, e.g. for the somatostatin analogOctreotide®, verification of these tumors is unproblematic. Ifcorresponding receptors are not expressed, however, they evadescintigraphic verification. In addition to localization diagnosis,radioactive labeled peptides also allow for an approach to the treatmentof tumors in which one can implement a specific receptor-directedradiopeptide therapy through labeling a somatostatin analog, e.g.Octreotide®, with an appropriate radionuclide (α- or β-emitter). Thefact that the corresponding radionuclides are bound chemically by thepeptide (e.g. through complexation with a metal chelator which waspreviously bound to that peptide) in such a way that they will indeed beabsorbed by the tumor cells but can no longer be discharged, results ina high specific accumulation in the tumor tissue.

However, a whole series of neuroendocrine tumors (NET), among theminsulinomas and small cell bronchial carcinomas, do not express thenecessary subtypes of the somatostatin receptor which are essential forSRS or radiopeptide therapy with the somatostatin analog Octreotide®. Asubstantial percentage of insulinomas in particular are not detectableby scintigraphic diagnosis. In small cell bronchial carcinomas SRS alsodoes not constitute an appropriate method as, although primary tumorsare often visible, metastases are not able to be shown due to loss ofreceptor expression. Consequently they are inaccessible for radiopeptidetherapy, which presents an interesting additional or alternative therapymethod. Therefore the need exists for an appropriate peptide, which willbe absorbed by the previously mentioned tumors.

The incretin hormone glucagon-like peptide-1 (GLP-1), as well as itsanalogs exendin-3 and exendin-4 (from the saliva of the gila monsterHeloderma horridum and Heloderma suspectum), are peptides, for whichinsulinomas and small cell bronchial carcinomas—along with many otherkinds of tumors—express receptors. Insulinomas originate from theinsulin producing (3-cells in the islet of Langerhans in the pancreas,in which GLP-1 as well as exendin-3 and exendin-4 elicit a postprandialinsulin secretion.

TECHNICAL STATE OF THE ART

For the utilization of glucagon-like peptide-1 (GLP-1) in scintigraphyit is necessary to label the peptide. The method for that and for thelabeling of proteins with radionuclides is known to the expert anddocumented in numerous patent applications (e.g. DE 690 18 226 T2) andscientific publications. The peptides described there for application indiagnostic imaging and for the exchange of therapeutically effectivemolecules in pathological tissue are normally inserted on the N-terminalend through an amino in the peptide. The peptides must be furthermodified concurrently regarding stabilization.

The GLP-1 used in the US 2003/0232761A1 and its derivative GLP-1(7-37)are, for example, modified on the N-terminal end by one amino. Hence,the N-terminal end of GLP-1 is no longer available to bond a GLP-1receptor, therefore both receptor bonding and internalization isinadequate in these peptides. The latter are thus inappropriate forutilization in radiopeptide therapy of insulinomas and small cellbronchial carcinomas. As experience shows, a mutation, such as asubstitution of an amino acid within the sequence of peptides of GLP-1and exendin 3 or exendin 4, and their possible modifications through atherapeutic or a signalizing molecule most often causes damage to thepeptide structure, obstructing any further bonding to the receptor.

A further method for the modification of GLP-1, without affecting theN-terminus, is not known at this time. Furthermore, no GLP-1 derivativesare known which are appropriate, either labeled or unlabeled, for use inthe radiotherapy of insulinomas and small cell bronchial carcinomas.

Task

The task of the invention at hand, therefore, is to eliminate thedeficiency of the technological state of the art and make peptidesavailable which can be labeled and still bond the GLP-1 receptor withthis labeling and be utilized in the production of an agent for thediagnosis and therapy of diseases, in which the expression of the GLP-1receptor plays a role.

Solution of the Task

This task is solved, based on the present invention, by the claims,through peptide derivatives of GLP-1, exendin-3 and exendin-4, which aremodified by an amino at the C-terminus and bond via the N-terminus atthe GLP-1 receptor as well as chimeric peptides of GLP-1 with exendin-3or exendin-4. These peptide derivatives as well as the chimeric peptidesare being unlabeled or labeled in order to be utilized in the productionof an agent for diagnostic and therapy of benign or malignant diseasesin which GLP-1 receptor expression plays a role.

Through these peptide derivatives of GLP-1, exendin-3 and exendin-4 aswell as chimeric peptides of GLP-1, exendin-3 or exendin-4 theproduction of a means for scintigraphic applications is carried outwhich will be utilized for diagnostic and therapy of GLP-1 receptorexpressing tumors, including NET (especially from insulinomas) and smallcell bronchial carcinomas.

This is possible for the first time, as the peptide derivatives based onthe current invention are modified by an amino at the C-terminus, makingthus available the N-terminus for bonding to the GLP-1 receptor.

Through the bonding of the peptide derivatives based on the currentinvention, for instance radioactively labeled, and chimeric peptides ofGLP-1, exendin-3 and exending-4 to the GLP-1 receptor, therepresentation of GLP-1 receptor expressing tumors is possible, enablinghereby a considerable improvement of the patients' medical care. NET areabove all, gastroenteropancreatic NET, such as insulinomas, for which todate no non-invasive method with sufficient sensitivity is available orof small cell bronchial carcinomas localized in the area of the lung inwhich case the specific differentiation between inflammable processesand tumors or metastases is neither possible by means of a non-invasivemethod.

Furthermore, by means of the peptide derivatives and the chimericpeptides, both based in the current invention, the density of insulinproducing cells within the pancreas as well as the expression of GLP-1receptors in vivo and in vitro are visualized. This is for instance inthe representation of GLP-1 receptor expressing cells in the case of thediabetes mellitus a in vivo representation, as these are the cells whichalso secrete insulin. The representation of the GLP-1 receptor densitywithin the pancreas is particularly important in the case of patientswith diabetes mellitus during and after therapy with pharmaceuticals.

Additionally the distribution of GLP-1 receptors in malignant and benigntissues is represented. The articulated questions are hereby both ofclinical as well as of scientific nature, as there is to date no allinclusive data available concerning the arrangement of GLP-1 receptorsin human beings.

Thus, the advantage of the current invention is that peptide derivativesof GLP-1 (glucagon-like peptide-1), exendin-3 and exendin-4 as well aschimeric peptides of GLP-1, exendin-3 or exendin-4 are utilized for theproduction of an agent, especially for the receptor-oriented specificrepresentation and therapy, particularly of NET, in the case at handespecially of insulinomas and small cell bronchial carcinomas.

A GLP-1 receptor scintigraphy is particularly applicable in thediagnosis of small cell bronchial carcinomas, allowing for the firsttime the specific detection of metastases within lymph nodes (lymphnodes changed by inflammation versus lymph nodes attacked bymetastases).

The application of peptide derivatives from (glucagon-like peptide-1),exendin-3 and exendin-4, as well as chimeric peptide from GLP-1,exendin-3 or exendin-4 according to the current invention remains anagent of diagnostic and therapy for all malignant and benign diseases inwhich GLP-1 receptor expression plays a role, in particular in thefollowing: as a contrast agent in Magnetic Resonance Imaging (MRI); as aradioactive agent in scintigraphy (SPECT, Single Photon EmissionComputed Tomography) as well as in radiopeptide therapy; in PET(Positron Emissions Tomography); in receptor-mediated chemotherapy; andin optical diagnostic. Optical diagnostic here means the stimulation ofa fluorescent molecule by a particular wave length, inducing asuccessive light emission of a different wave length. It is the emittedwave length which is detected.

An expert can easily choose the kind of labeling at the C-terminus ofthe peptide derivative from GLP-1 (glucagon-like peptide-1), exendin-3and exendin-4 as well as the chimeric peptides from GLP-1, exendin-3 orexendin-4 depending on the desired application: for example, forscintigraphy or radiotherapy from radioactive nuclides; for contrastagent in Magnetic Resonance Imaging (MRI) from gadolinium; and forendoscopic or scientific examinations from fluorescent pigments.

According to the current invention malignant diseases are those in whichthe affected tissue shows changes in its level of differentiation ascompared to healthy tissue, invasive growth or a spreading of its tissueinto the blood stream or lymphatic system. All neuroendocrine tumorsfall into this category, in particular those of the gastrointestinaltract; especially insulinomas, bronchial carcinomas, pancreaticcarcinomas and all other malignant diseases which are connected to theover-expression of GLP-1 receptors.

According to the current invention benign diseases are thosecharacterized by the fact the affected tissue does not significantlylose its level of differentiation, shows no invasive growth and does nothave any tissue metastasis into the blood stream or lymphatic system.This includes, for example, diabetes mellitus, but also eating disordersof disorders of the psyche.

Characterization of Peptide Derivatives and Chimeric Peptides

Surprisingly it was found that peptide derivatives from GLP-1, exendin-3and exendin-4, as well as chimeric peptides from GLP-1, exendin-3 orexendin-4, which are modified via an amino at the C-terminus, bond atthe N-terminus to the GLP-1 receptor. They even shown a high degree ofaffinity to the GLP-1 receptor, as do natural peptides. Experiments withtumor carrying hairless mice show a specific uptake in GLP-1 receptorsof positive tumor tissue.

Peptide derivatives as well as chimeric peptides according to thecurrent invention are unlabelled or, via a chelator at the C-terminusamino, labeled as an agent for application in the diagnostic and therapyof benign and malignant diseases in which GLP-1 receptor expressionplays a role. The type of labeling here consists mainly of a radiometal,a MRI contrast agent, a fluorescent chromophore or a chemotherapeuticagent.

The process and method of labeling are well known to an expert (e.g. DE690 18 226 T2), which take place, for example, through the coupling ofradionuclides, non-magnetic metals and other MRI contrast agents orfluorescent pigments; this means that the bonding of the receptors orthe internalization of the peptide derivatives, as well as the chimericpeptides according to the current invention, are not impaired and theGLP-1 receptor bonding N-terminus remains free (unlinked).

The sequences of amino acids of the original peptides:

GLP-1:H-His-Asp-Glu-Phe-Glu-Arg-His-Ala-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17  18Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys-Glu-Phe-Ile-Ala-Trp-Leu-Val-Lys-Gly-Arg-Gly-OH19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37Exendin-3:H-His-Ser-Asp-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17  18Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37Pro-Ser-NH₂ 38  39 Exendin-4:H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Giu-Glu-Glu-Ala-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17  18Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37Pro-Ser-NH₂ 38  39

According to the current invention the following peptide derivatives ofGLP-1 (1-37), exendin-3 and exendin-4 are produced:

GLP-1(x-y)A¹⁻³⁷Exendin-3 (z-k)A¹⁻⁴⁰Exendin-4 (z-k)A¹⁻⁴⁰

Whereby:

x=amino acids 1-36 of the GLP-1 amino acid sequencey=amino acids 2-37 of the GLP-1 amino acid sequencez=amino acids 1-38 of the exendin-3 or exendin-4 amino acid sequencek=amino acids 2-39 of the exendin-3 or exendin-4 amino acid sequence

A=Attachment group consisting of one or more amino acid or itsderivative as a signal molecule, or to bond signal molecules or tostabilize them. The preference is for A to be located at the C-terminusand the amino is preferably lysine or alternatively another amino acidwith a free amino, e.g. ornithine or an organic group with a free aminoonto which a chelator is coupled for the labeling with radionuclides ora MRI contrast agent, fluorescent pigments or a chemotherapeutic agent.

Chelators which can be used include DTPA (diethylenetriaminepentaaceticacid), alternatively N,N-Bis(2-[bis(carboxymethyl)amino]-ethyl)glycine),alternatively DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra-aceticacid), HYNIC (6-hydrazinopyridin-3-carbonic acid), MAG3(mercaptoacetyl-glycylglycylglycine), N4 (1,4,8,11-tetraazaundecane) andall known derivatives of the above named chelators.

The exponent indicates at which position the attachment groupalternatively can be found within the amino acid sequence.

GLP-1(x-y)A¹⁻³⁷

Here GLP-1 derivatives of different lengths are included, whereby x canaccept the numbers 1 to 36, which is smaller than y, which accepts thenumbers 2 to 37. A is the attachment group which can be placed at anyposition, preferably however at the C-terminus and is one higher than y.Preferably, the attachment group is the amino lysine.

Exendin-3 (z-k)A¹⁻⁴⁰

Here exendin-3 derivatives of different lengths are included, whereby zcan accept the numbers 1 to 38, which is smaller than k, which acceptsthe numbers 2 to 39. A is the attachment group which can be placed atany position, preferably, however, at the C-terminus and is one higherthan y. Preferably, the attachment group is the amino lysine.

Exendin-4 (z-k)A¹⁻⁴⁰

Here exendin-4 derivatives of different lengths are included, whereby zcan accept the numbers 1 to 38, which is smaller than k, which acceptsthe numbers 2 to 39. A is the attachment group which can be placed atany position, preferably, however, at the C-terminus and is one higherthan y. Preferably, the attachment group is the amino lysine.

The following peptide derivatives are particularly preferred:

1. MC 10: (DTPA-Lys³⁷) GLP1 (7-36) amide2. MC 13: (DTPA-Lys⁴⁰) exendin-3 amide3. MC 11: (DTPA-Lys⁴⁰) exendin-4 amide

The synthesis takes place, for example, in the company Peptide SpecialtyLaboratories GmbH according to the Merrifield method and purificationvia HPLC.

MC 10 (DTPA-Lys³⁷) GLP1 (7-36) amide consists of the amino acids 7-36 ofGLP-1, carrying at the C-terminal end as an amino acid with a freeamino, preferably lysine at position 37 as well as the chelator DTPA.

MC 13 (DTPA-Lys⁴⁰) exendin-3 amide consists of the complete amino acidsequence of exendin-3, carrying at the C-terminal end as an amino acidwith a free amino, preferably lysine at position 40 as well as thechelator DTPA.

MC 11 (DTPA-Lys⁴⁰) exendin-4 amide consists of the complete amino acidsequence of exendin-3, carrying at the C-terminal end as an amino acidwith a free amino, preferably lysine at position 39 as well as thechelator DTPA.

According to the current invention the following chimeric peptides fromGLP-1 (1-37) and exendin-3 or exendin-4 are produced:

GLP-1(x-y) exendin-3(z-k)A¹⁻⁷⁵GLP-1(x-y) exendin-4(z-k)A¹⁻⁷⁵Exendin-3(z-k) GLP-1(x-y)A¹⁻⁷⁵Exendin-4(z-k) GLP-1(x-y)A¹⁻⁷⁵

Here the following applies:

x=amino acids 1-36 of the GLP-1 amino acid sequencey=amino acids 2-37 of the GLP-1 amino acid sequencez=amino acids 1-38 of exendin-3 or exendin-4 amino acid sequencek=amino acids 2-39 of exendin-3 or exendin-4 amino acid sequence

A=Attachment group consisting of one or more amino acid or itsderivative as a signal molecule, or to bond signal molecules or tostabilize them. The preference is for A to be located at the C-terminusand the amino is preferably lysine or alternatively another amino acidwith a free amino, e.g. ornithine or an organic group with a free aminoonto which a chelator is coupled for the labeling with radionuclides ora MRI contrast agent, fluorescent pigments or a chemotherapeutic agent.

Chelators which can be used include DTPA (diethylenetriaminepentaaceticacid), alternatively N,N-Bis(2-[bis(carboxymethyl)amino]-ethyl)glycine),alternatively DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra-aceticacid), HYNIC (6-hydrazinopyridin-3-carbonic acid), MAG3(mercaptoacetyl-glycylglycylglycine), N4 (1,4,8,11-tetraazaundecane) andall known derivatives of the above named chelators.

The exponent indicates at which position the attachment groupalternatively can be found within the amino acid sequence.

GLP-1(x-y) exendin-3(z-k)A¹⁻⁷⁵

Here chimeric peptides from GLP-1 and exendin-3 are included, in whichthe amino acids 1 to 36 come from GLP-1 and then after that the aminoacids 1 to 39 from exendin-3. A is the attachment group which can beplaced at any position, preferably, however, at the C-terminus, and isone higher than the number of amino acids from GLP-1 and exendin-3,preferably the amino lysine.

GLP-1(x-y) exendin-4(z-k)A¹⁻⁷⁵

Here chimeric peptides from GLP-1 and exendin-3 are included, in whichthe amino acids 1 to 36 come from GLP-1 and then after that the aminoacids 1 to 39 from exendin-4. A is the attachment group which can beplaced at any position, preferably, however, at the C-terminus, and isone higher than the number of amino acids from GLP-1 and exendin-4,preferably the amino lysine.

Exendin-3(z-k) GLP-1(x-y)A¹⁻⁷⁵

Here chimeric peptides from exendin-3 and GLP-1 are included, whereby zcan accept the numbers 1 to 38, but is smaller than k, which can acceptthe numbers 2 to 39. A is the attachment group which can be placed atany position, preferably, however, at C-terminus and is one higher thany. Preferably, the attachment group is the amino lysine.

Exendin-4(z-k) GLP-1(x-y)A¹⁻⁷⁵

Here chimeric peptides from exendin-4 and GLP-1 are included, whereby zcan accept the numbers 1 to 38, but is smaller than k, which can acceptthe numbers 2 to 39. A is the attachment group which can be placed atany position, preferably, however, at C-terminus and is one higher thany. Preferably, the attachment group is the amino lysine.

Exemplary for a chimeric GLP-1(x-y) exendin-3(z-k)A¹⁻⁷⁵ or GLP-1(x-y)exendin-4(z-k)A¹⁻⁷⁵ peptide is MC12, consisting of GLP-1 (7-36) exendin(33-39) Lys amide (Synthesis takes place in the company PeptideSpecialty Laboratories GmbH according to the Merrifield method andpurification via HPLC.).

MC 12: (Ser³⁷, Gly³⁸, Ala³⁹, Pro⁴⁰, Pro⁴¹, Pro⁴², Ser⁴³, DTPA-Lys⁴⁴amide) GLP1 (7-36)

MC 12 consists of the complete amino acid sequence of GLP-1 (7-36),carrying at the C-terminal end an amino, preferably lysine at position44 as well as the chelator DTPA, as well as a chain of 7 amino acidsfrom exendin (33-39) Lys amide. Thus there is a chimeric peptide GLP-1(7-36) exendin (33-39)Lys amide.

It is clear to the expert that hereby peptide derivatives of differentlengths from GLP-1, exendin-3 and exendin-4, as well as chimericpeptides of different lengths from GLP-1, exendin-3 or exendin-4 exist,which contain various combinations of the amino acid sequences fromGLP-1, exendin-3 and exendin-4 on which they are based.

The peptide derivatives from GLP-1, exendin-3 and exendin-4, as well aschimeric peptides from GLP-1, exendin-3 or exendin-4 based on thecurrent invention, which are modified by an amino at the C-terminus andbond via the N-terminus at the GLP-1 receptor, also include moleculeswhich are distinguishable at one or more positions from the peptideGLP-1, exendin-3 and exendin-4 described above and have a high degree ofhomology to those sequences. Homology here means a sequence identity ofat least 40%, in particular an identity of 60%, preferably over 80% andespecially preferably over 90%. The deviation to the amino acidsequences described above could arise through deletion, substitutionand/or insertion

Furthermore, the chimeric peptides from GLP-1, exendin-3 or exendin-4according to the current invention are also produced without anymodifications to the C-terminus. They are particularly used in theproduction of an agent for the therapy of diabetes.

GLP1(x-y) exendin-3(z-k) GLP1(x-y) exendin-4(z-k)Exendin-3(z-k) GLP1(x-y)Exendin-4(z-k) GLP1(x-y)

MC 20: (Ser³³, Gly³⁴, Ala³⁵, Pro³⁶, Pro³⁷, Pro³⁸, Ser³⁹) exendin GLP1(7-36)

MC 20 consists of the complete amino acid sequence of GLP-1 (7-36),carrying at the C-terminal end a chain of 7 amino acids from exendin(33-39). Thus there is an unmodified chimeric peptide GLP-1 (7-36)exendin (33-39).

Labeling of the Peptide Derivatives and the Chimeric Peptides

Peptide derivatives as well as chimeric peptides according to thecurrent invention are dissolved in a suitable stabilizing buffer, forexample, in order to stabilize metals, preferably in 0.5 M sodiumacetate pH 5.4 with a concentration of approx. 10⁻³ M. Alternatively,for the stabilization of fluorescent pigments a buffer of ammoniumacetate is preferable; for the stabilization of chemotherapeutic agentand contrast agents a physiological buffer is preferable.

The labeling occurs at the attachment group A through the coupling ofradionuclides, MRI contrast agents, fluorescent pigments orchemotherapeutic agent. Different methods are applied according towhether the application will be in vitro or in vivo.

The following are used as radionuclides for covalent or complexcoupling:

Procedure in which Emitted Type of Nuclide applied t_(1/2) [h] radiationEnergy [keV] coupling F-18 PET 1.8 β⁺ 634 covalent Cu-64 PET 12.7 β⁺1673  complex Cu-67 therapy 61.8 β⁻ 391 complex γ 184 Ga-67 SPECT 79.2 γ 93/184/300 complex Ga-68 PET 1.1 β⁺ 2921  complex Y-86 PET 14.8 β⁺1220  complex γ 1076/1153 Y-90 therapy 64.1 β⁻ 2280  complex Tc-99mSPECT 6 γ 140 complex In-111 SPECT 67.2 γ 171/245 complex I-123 SPECT13.2 γ 158 covalent I-124 PET 101 β⁺ 2137/1534 covalent γ 602 I-131therapy 192 γ 364 covalent β⁻ 606 Lu-177 therapy 158 γ 208 complex β⁻112/208 Re-186 therapy 88.8 γ 137 complex β⁻ 1071  Re-188 therapy 17 γ155/477/632 complex β⁻ 1965/2120 Pt-193m therapy 104 γ 135 complex augere⁻ Pt-195m therapy 96 γ  98 complex auger e⁻ Ac-225 therapy 240 γ 99,150 complex α At-211 therapy 7.2 γ 687 complex auger e⁻ covalent Bi-213therapy 0.76 γ 440 complex α Sm-153 therapy 46 γ 103 complex β⁻ Er-169therapy 226 β⁻ 100 complex PET (Positron Emissions Tomography), SPECT(Single Photon Emissions Computed Tomography)

Fluorescent pigments/chromophores such as the following were used:Fluorescein, Rhodamin, Coumarin, BODIPY, Pyrene (Cascade Blue), LuciferYellow, Phycobiliprotein, Cyanin, AlexaFluoro, Oregon Green, Texas Redand their derivatives.

Chelators which can be used include DTPA (diethylenetriaminepentaaceticacid), alternatively N,N-Bis(2-[bis(carboxymethyl)amino]-ethyl)glycine),alternatively DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra-aceticacid), HYNIC (6-hydrazinopyridin-3-carbonic acid), MAG3(mercaptoacetyl-glycylglycylglycine), N4 (1,4,8,11-tetraazaundecane) andall known derivatives of the above named chelators.

MRI contrast agents which can be used include: gadolinium, manganese,iron, europium, copper, nickel, chrome, prasodymium, dysprosium orholmium or their compounds, but also the negative MRI contrast agentssuch as perfluorocarbone, as well as isotopes such as such as F-19, H-1,P-31, Na-19 for MRI spectroscopy. Negative MRI contrast agents accordingto the current invention are those which obliterate the MRI signal orgreatly weaken it, i.e. not amplifying it.

Chemotherapeutic agents which can be used include: alkylating agents,intercalators, antimetabolite, enzyme inhibitors and blockers andspindle poisons (for example alkylsulfonate, ethylimine, nitrosomonas(N. ureae), nitrogen mustard derivatives, folic acid analogs, purineanalogs, pyrimidine analogs, podophyllin derivatives, taxane,vincaalcaloide, anthracycline, other cytostatic antibiotics, platinumcompounds, campthotecin derivatives, different hormones, growth factors,interferons or interleukins), otherwise the chemotherapeutic agentsdescribed in “Onkologie 2004/05”, authors Preiss, Dornhoff, Hagmann,Schmieder, published by Zuckschwerdtverlag, at pp. 230-287, but also allother cytostatic or cytotoxic substances.

Depending on the type of application in which the protein derivativesand chimeric proteins according to the current invention are used, andthe agent produced with the above mentioned proteins for diagnostic andtherapy of benign and malignant diseases, in which GLP-1 receptorexpression plays a role, the labeling reaction will be carried out intwo variations.

Labeling for in vitro application in radiotherapy

3 μL of the peptide derivative or the chimeric peptide according to theinvention which has been dissolved in a suitable stabilizing buffer,preferably 0.5 M sodium acetate pH 5.4 with a concentration of approx.10⁻³ M, are added to 500 μL 0.5 M sodium acetate pH 5.4 for the purposeof labeling. The pH-value is between 3 and 6. Then 185 MBq ¹¹¹InCl₃(Tyco, Petten, The Netherlands) in 0.1 M HCl 500 μL is added andincubated for 30 minutes at 37° C. Finally 3 μL 10⁻³ M solution^(nat)InCl₃ is added, followed by a further incubation for 30 min inorder to saturate all bond sites.

Quality control is carried out via a HPLC column:

Column: CC 250/4.6 Nucleosil 120-5 C18 (Machery-Nagel, Oenisingen,Switzerland)

Gradient: 0->5 min 100% 0.05 M NH₄OOCCH₃, pH 5.4 (buffer A); 5->25 min100% buffer A->50% buffer N50% acetone nitrile.Quality control for an in vitro application is fulfilled with a labelingyield of over 98%.

Thus a radioactive labeled agent is available for diagnostic and therapyof benign and malignant diseases, in which GLP-1 receptor expressionplays a role, which can, for example, which can be employed in cell andtissue cultures of pancreatic cells.

Labeling for In Vivo Application in Radiotherapy

3 μL of the peptide derivative or the chimeric peptide according to theinvention which has been dissolved in a suitable stabilizing buffer,preferably 0.5 M sodium acetate pH 5.4 with a concentration of approx.10⁻³ M, are added to 500 μL 0.5 M sodium acetate pH 5.4 for the purposeof labeling. Finally 185 MBq ¹¹¹InCl₃ (Tyco, Petten, The Netherlands) in0.1 M HCl 500 μL is added and incubated for 30 minutes at 37° C. Qualitycontrol is carried out via a HPLC-Column:

Column: CC 250/4.6 Nucleosil 120-5 C18 (Machery-Nagel, Oenisingen,Switzerland)

Gradient: 0->5 min 100% 0.05 M NH₄OOCCH₃, pH 5.4 (buffer A); 5->25 min100% buffer A->50% buffer A/50% acetone nitrile.

Quality control for an in vivo application is fulfilled with a labelingyield of over 98%.

Thus a radioactive labeled agent is available for diagnostic and therapyof benign and malignant diseases, in which GLP-1 receptor expressionplays a role, which can, for example, be employed to detect tumors inpatients.

The term “patient” refers to humans and vertebrates alike. Thus, theagent can be applied both in human and veterinary medicine. Thetherapeutically and diagnostically effective agent based on the currentinvention is given to patients as part of an acceptable pharmaceuticalcomposition in one of the following forms: oral, rectal, parenteral,intravenous/intraarterial, intramuscular, subcutaneous, intrathecal,intracisternal, intracranial, intravaginal, intraperitoneal,intravascular, local (powder, ointment or drops) or spray form(aerosol).

The required dose is to be determined by a doctor in each individualcase of diagnostic and therapy of benign and malignant diseases, inwhich GLP-1 receptor expression plays a role.

Internalization Study

The internalization study shows, in exemplary manner, the transport intothe cell of the peptide derivatives and chimeric proteins, both in vitroradioactively labeled, according to the current invention.

In a 6 well plate 100,000 GLP-1 receptor transfected CHO cells are sown.The cells grow until they are confluent. Then 4 groups are formed:

Group 1: Complete Bonding, Washed with PBS

100,000 cpm ¹¹¹In (10⁻¹⁵ Mol) labeled peptide is added to 2 mL mediumand incubated for 1 h at 37° C. Then it is washed 3× with PBS and thecells are separated with 20 mM MOPS(3-Morpholinopropanesulfonic-acid)+0.1% Triton-X-100 (ph7.4). The uptakeinto the cells is measured with a γ-counter. The number of cells ismeasured by the protein content, using the protein assay kit fromBio-Rad (Munich, Germany), based on the Bradford method. The results aregiven in proteins cpm/μg.

Group 2: non-Specific Bonding, Washed with PBS

20 μL of a 10⁻³ M GLP-1 solution and 100,000 cpm ¹¹¹In labeled peptideare added to 2 mL medium and incubated for 1 h at 37° C. Then it iswashed 3× with PBS and the cells are separated with 20 mM MOPS(3-Morpholinopropanesulfonic-acid)+0.1% Triton-X-100 (ph7.4). The uptakeinto the cells is measured with a γ-counter. The number of cells ismeasured by the protein content, using the protein assay kit fromBio-Rad (Munich, Germany), based on the Bradford method. The results aregiven in proteins cpm/μg.

Group 3: Complete Bonding, Washed with Acid

20 μL of a 10⁻³ M GLP-1 solution and 100,000 cpm ¹¹¹In labeled peptideare added to 2 mL medium and incubated for 1 h at 37° C. Then it iswashed 1× with 0.1 M sodium acetate buffer pH 4 and 2× with PBS and theCells are separated with 20 mM MOPS(3-Morpholinopropanesulfonic-acid)+0.1% Triton-X-100 (ph7.4). The uptakeinto the cells is measured with a γ-counter. The number of cells ismeasured by the protein content, using the protein assay kit fromBio-Rad (Munich, Germany), based on the Bradford method. The results aregiven in proteins cpm/μg.

Group 4: Non-Specific Bonding, Washed with Acid

20 μL of a 10⁻³ M GLP-1 solution and 100,000 cpm ¹¹¹In labeled peptideare added to 2 mL medium and incubated for 1 h at 37° C. Then it iswashed 1× with 0.1 M sodium acetate buffer pH 4 and 2× with PBS and thecells are separated with 20 mM MOPS(3-Morpholinopropanesulfonic-acid)+0.1% Triton-X-100 (ph7.4). The uptakeinto the cells is measured with a γ-counter. The number of cells ismeasured by the protein content, using the protein assay kit fromBio-Rad (Munich, Germany), based on the Bradford method. The results aregiven in proteins cpm/μg.

${{Evaluation}\text{:}\mspace{14mu} \% \mspace{14mu} {IDsB}} = {\frac{{{Res}\; 3.} - {{Res}\; 4.}}{{{Res}\; 1.} - {{Res}\; 2.}}*100}$

% IdsB=% of internalization of the specific bonding

% IdsB MC10 75 ± 5 MC11 70 ± 7 MC12 73 ± 9

The results show that a good transport has taken place into the cells.

Bonding Studies

Bonding studies show the specific bonding which takes place via thevivo-labeling radioactive labeled peptide derivatives and chimericproteins according to the current invention onto the GLP-1 receptor.

In a 6-well plate 100,000 GLP-1 receptor transfected CHO cells are sown.The cells grow until they are confluent. Then 2 mL 100,000 cpm ¹¹¹Inlabeled peptide is added. In order to test the bonding it is thenblocked with 20 μL of a 10⁻³ M GLP-1 solution.

% Blocking MC10 80 ± 3 MC11 85 ± 3 MC12 77 ± 6

The in vivo bio-distribution can, for example, be shown in rodents suchas hairless mice. For this purpose GLP-1 transfected CHO cells areinjected into hairless mice. After approx. 3 to 5 weeks tumors approx.300 mg in size had grown. The mice are then injected in a tail vein with37 MBq ¹¹¹In labeled peptide according to the invention and are measuredafter 4 h under a γ-camera.

In the course of this procedure there was quick clearance via thekidneys and an uptake in the kidneys. There was also a high uptake inthe GLP-1 receptor positive tumor, whereas the GLP-1 receptor negativetumor barely showed any uptake. There was also a slight uptake in thepancreas; other organs showed no visible uptake.

Ex vivo bio-distribution studies are conducted in groups of 4 mice each,in which 555 kBq In-111 labeled MC10 is injected into the tail vein. 1,4 and 24 h p.i. all the mice are killed and their organs removed.

The uptake of radioactivity is measured and the organs are weighed. The% of injected dose program of organ weight is calculated.

The results are as follows:

Organ 1 h Stadev 4 h Stadev 24 h Stadev Blood 0.01 0.00 0.00 0.00 0.000.00 Liver 0.03 0.01 0.01 0.01 0.01 0.00 Stomach 0.14 0.10 0.13 0.070.07 0.06 Spleen 0.02 0.02 0.01 0.00 0.01 0.00 Pancreas 0.58 0.50 0.620.28 0.37 0.27 Kidneys 7.90 3.62 7.41 3.56 4.85 3.05 Intestine 0.12 0.060.07 0.06 0.04 0.03 Lungs 0.80 0.56 0.36 0.17 0.22 0.07 Heart 0.02 0.010.01 0.01 0.00 0.00 Bones 0.02 0.04 0.01 0.00 0.01 0.01 Muscle 0.01 0.000.00 0.00 0.00 0.00 Tumor− 0.03 0.03 0.02 0.01 0.01 0.00 Tumor+ 0.420.19 0.31 0.30 0.20 0.16

Mean value from the bio-distribution with 4 mice pro group in % i.D./gStadev: standard deviation.

1. Peptide derivatives of GLP-1 and exendin-3, wherein their C-terminusis modified by an amine and wherein their N-terminus binds to the GLP-1receptor.
 2. Peptide derivatives of GLP-1 and exendin-3 according toclaim 1 wherein they contain completely or partly the amino acidsequences of the peptides GLP-1 (1-37):H-His-Asp-Glu-Phe-Glu-Arg-His-Ala-Glu-Gly-Thr-Phe-Thr-Ser-Asp-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys-Glu-Phe-Ile-Ala-Trp-Leu-Val-16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33Lys-Gly-Arg-Gly-OH 34  35  36  37

and exendin-3:H-His-Ser-Asp-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38 
 39.


3. Peptide derivatives of GLP-1 and exendin-3 according to claim 1,wherein they are based on GLP1(x-y)A¹⁻³⁷ or exendin-3 (z-k)A¹⁻⁴⁰ with xrepresenting the amino acids 1-36 of the GLP-1 amino acid sequence, yrepresenting the amino acids 2-37 of the GLP-1 amino acid sequence, zrepresenting the amino acids 1-38 of the exendin-3 amino acid sequence,k representing the amino acids 2-39 of the exendin 3 amino acid sequenceand A being an attachment group comprising of one or more amino acids orits derivatives as a signal molecule, or to bond signal molecules or tostabilize them, whereby the exponent indicates at which position theattachment group can be found within the amino acid sequence.
 4. Peptidederivatives from GLP-1 and exendin-3 according to claim 3, wherein theattachment group A is preferably located at the C-Terminus andrepresents an amine.
 5. Peptide derivatives from GLP-1 and exendin-3according to claim 3, wherein the attachment group A is preferablylysine.
 6. Peptide derivatives from GLP-1 and exendin-3 according toclaim 3, wherein the attachment group A is an amino acid, such asornithine, or an organic group comprising free amine.
 7. Peptidederivatives from GLP-1 and exendin-3 according to claim 3, wherein achelator is coupled with attachment group A for the labeling withradionuclides or a MRI contrast agent, fluorescent pigments or achemotherapeutic agent.
 8. Peptide derivatives from GLP-1 and exendin-3according to claim 7, wherein the chelator isN,N-Bis(2-[bis(carboxymethyl)amino]-ethyl)glycine), DOTA(1,4,7,10-Tetraazacyclodo-decane-1,4,7,10-tetra-acetic acid), HYNIC(6-Hydrazinopyridin-3-carbonic acid), MAG3(mercaptoacetyl-glycylglycylglycine), N4 (1,4,8,11-tetraazaundecane) andall known derivatives, preferably DTPA (Diethylenetriaminepentaaceticacid).
 9. Peptide derivatives from GLP-1 and exendin-3 according toclaim 7, wherein the labeling is a coupling of radionuclides, MRIcontrast agent, fluorescent pigments and/or a chemotherapeutic agent.10. Peptide derivatives from GLP-1 and exendin-3 according to claim 7,wherein the chosen fluorescent pigments are in particular from the groupFluorescein, Rhodamin, Coumarin, BODIPY, Pyrene (Cascade Blue), LuciferYellow, Phycobiliprotein, Cyanin, AlexaFluoro, Oregon Green, Texas Redand their derivatives.
 11. Peptide derivatives from GLP-1 and exendin-3according to claim 7, wherein the chosen radionuclide is in particularfrom the group F-18, Cu-64, Cu-67, Ga-67, Ga-68, Y-86, Y-90, Tc-99m,In-111, I-123, I-124, I-131, Lu-177, Re-186, Re-188, Pt-193m, Pt-195m,Ac-225, At-211, Bi-213, Sm-153 or Er-169.
 12. Peptide derivatives fromGLP-1 and exendin-3 according to claim 7, wherein the chosen MRIcontrast agent is in particular selected from the group comprisinggadolinium, manganese, iron, europium, copper, nickel, chrome,prasodymium, dysprosium or holmium or their compounds orperiluorocarbone or F-19, H-1, P-31, Na-19.
 13. Peptide derivatives fromGLP-1 and exendin-3 according to claim 7, wherein the chosenchemotherapeutic agent is in particular selected from the groupcomprising alkylating agents, ethylimine, nitrosomonas (N. ureae),nitrogen mustard derivatives, folic acid analogs, purine analogs,pyrimidine analogs, podophyllin derivatives, taxane, vincaalcaloide,anthracycline, other cytostatic antibiotics, platinum compounds,campthotecin derivatives, hormones, growth factors, interferons orinterleukins or cytostatic or cytotoxic substances.
 14. Peptidederivatives from GLP-1 and exendin-3 according to claim 7, wherein thelabeling via the coupling of radionuclides for in vitro applicationstakes place through the saturation of the bonding sites with^(nat)InCL₃.
 15. Chimeric peptides from GLP-1 and exendin, with exendinbeing exendin 3, wherein they contain completely or in part the aminoacid sequences of the peptides GLP-1 (1-37)H-His-Asp-Glu-Phe-Glu-Arg-His-Ala-Glu-Gly-Thr-Phe-Thr-Ser-Asp-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys-Glu-Phe-Ile-Ala-Trp-Leu-Val-16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33Lys-Gly-Arg-Gly-OH 34  35  36  37

and exendin-3:H-His-Ser-Asp-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38 
 39.


16. Chimeric peptides from GLP-1 and exendin according to claim 15,wherein they are based on: GLP1(x-y) exendin-3(z-k), or exendin-3(z-k)GLP1(x-y) with x representing the amino acids 1-36 of the GLP-1 aminoacid sequence, y representing the amino acids 2-37 of the GLP-1 aminoacid sequence, z representing the amino acids 1-38 of the exendin 3amino acid sequence, k representing the amino acids 2-39 of the exendin3 amino acid sequence.
 17. Chimeric peptides from GLP-1 and exendinaccording to claim 15, wherein they are based on: GLP1(x-y)exendin-3(z-k)A¹⁻⁷⁵, or exendin-3(z-k) GLP1(x-y)A¹⁻⁷⁵ with xrepresenting the amino acids 1-36 of the GLP-1 amino acid sequence, yrepresenting the amino acids 2-37 of the GLP-1 amino acid sequence, zrepresenting the amino acids 1-38 of the exendin-3 amino acid sequence,k representing the amino acids 2-39 of the exendin-3 amino acid sequenceand A being an attachment group comprising one or more amino acids orits derivatives as a signal molecule, or to bond signal molecules or tostabilize them, with the exponent indicating at which position theattachment group can be found within the amino acid sequence. 18.Chimeric peptides from GLP-1 and exendin according to claim 17, whereinthe attachment group A is preferably located at the C-Terminus andrepresents an amine.
 19. Chimeric peptides from GLP-1 and exendinaccording to claim 17, wherein the attachment group A is preferablylysine.
 20. Chimeric peptides from GLP-1 and exendin according to claim17, wherein the attachment group A is preferably an amino acid with afree amine, such as ornithine, or an organic group with a free amine.21. Chimeric peptides from GLP-1 and exendin according to claim 17,wherein a chelator is coupled with attachment group A for labeling withradionuclides or a MRI contrast agent, fluorescent pigments or achemotherapeutic agent.
 22. Chimeric peptides from GLP-1 and exendinaccording to claim 21, wherein the chelator isN,N-Bis(2-[bis(carboxymethyl)amino]-ethyl)glycine), DOTA(1,4,7,10-Tetraazacyclodo-decane-1,4,7,10-tetra-acetic acid), HYNIC(6-Hydrazinopyridin-3-carbonic acid), MAG3(mercaptoacetyl-glycylglycylglycine), N4 (1,4,8,11-tetraazaundecane) andtheir known derivatives, preferably DTPA (Diethylenetriaminepentaaceticacid).
 23. Chimeric peptides from GLP-1 and exendin according to claim17, wherein the labeling is a coupling of radionuclides, MRI contrastagent, fluorescent pigments and/or a chemotherapeutic agent. 24.Chimeric peptides from GLP-1 and exendin according to claim 17, whereinthe chosen fluorescent pigments are in particular selected from thegroup Fluorescein, Rhodamin, Coumarin, BODIPY, Pyrene (Cascade Blue),Lucifer Yellow, Phycobiliprotein, Cyanin, AlexaFluoro, Oregon Green,Texas Red and their derivatives.
 25. Chimeric peptides from GLP-1 andexendin according to claim 17, wherein the radionuclide is selected inparticular from the group F-18, Cu-64, Cu-67, Ga-67, Ga-68, Y-86, Y-90,Tc-99m, In-111, I-123, I-124, I-131, Lu-177, Re-186, Re-188, Pt-193m,Pt-195m, Ac-225, At-211, Bi-213, Sm-153 or Er-169.
 26. Chimeric peptidesfrom GLP-1 and exendin according to claim 17, wherein the chosen MRIcontrast agent is in particular from the group gadolinium, manganese,iron, europium, copper, nickel, chrome, prasodymium, dysprosium orholmium or their compounds or perfluorocarbone or F-19, H-1, P-31,Na-19.
 27. Chimeric peptides from GLP-1 and exendin according to claim17, wherein the chosen chemotherapeutic agent is in particular selectedfrom the group alkylating agents, ethylimine, nitrosomonas (N. ureae),nitrogen mustard derivatives, folic acid analogs, purine analogs,pyrimidine analogs, podophyllin derivatives, taxane, vincaalcaloide,anthracycline, other cytostatic antibiotics, platinum compounds,campthotecin derivatives, hormones, growth factors, interferons orinterleukins or cytostatic or cytotoxic substances.
 28. Chimericpeptides from GLP-1 and exendin according to claim 17, wherein thelabeling via the coupling of radionuclides for in vitro applicationstakes place through the saturation of the bonding sites with^(nat)InCL₃.
 29. Use of peptide derivatives from GLP-1 and exendin-3, aswell as chimeric peptides from GLP-1 and exendin-3 according to claim 1for the production of an agent for diagnostic and therapy of benign andmalignant diseases, in which the GLP-1 receptor expression plays a role.30. Application of peptide derivatives from GLP-1 and exendin-3, as wellas chimeric peptides from GLP-1 and exendin-3 according to claim 1 inorder to determine the density of insulin producing cells in a tissue.31. Application of peptide derivatives from GLP-1 and exendin-3, as wellas chimeric peptides from GLP-1 and exendin 3 according to claim 1 inorder to determine the expression of GLP-1 receptors or their density.32. Agent for the diagnostic and therapy of benign and malignantdiseases, in which GLP-1 receptor expression plays a role, wherein itcontains labeled peptide derivatives of GLP-1 and exendin 3, or labeledchimeric peptides from GLP-1 and exendin-3 according to claim
 1. 33.Agent for the diagnostic and therapy of benign and malignant diseases,in which GLP-1 receptor expression plays a role, wherein it containsunlabeled peptide derivatives from GLP-1 and exendin-3, or unlabeledchimeric peptides from GLP-1 and exendin-3 according to claim 1 andclaim
 16. 34. Agent according to claim 32 wherein the labeling containsa coupling of radionuclides, MRI contrast agents, fluorescent pigmentsand/or chemotherapeutic agent.
 35. Use of an agent according to claim 32for diagnostic and therapy of benign and malignant diseases, in whichGLP-1 receptor expression plays a role.
 36. Use of an agent according toclaim 32 for diagnostic and therapy of neuroendocrine tumors (NET),particularly insulinomas and small cell bronchial carcinomas.
 37. Use ofan agent according to claim 32 in scintigraphy, PET, SPECT, MRI, opticaldiagnostic, receptor-mediated chemotherapy, receptor-mediated,cytostatic or cytotoxic therapy and radiopeptide therapy.
 38. Use ofpeptide derivatives from exendin-4, wherein their C-terminus is modifiedby an amine and wherein their N-terminus binds to the GLP-1 receptor,with a sequence identity of over 90% to the amino acid sequence ofexendin-4:H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38  39

wherein the peptide derivatives are based on exendin-4 (1-39)A, with Abeing an attachment group comprising of one or more amino acids or itsderivatives as a signal molecule, or to bond signal molecules or tostabilize them, which is located at the C-terminus and represents anamine, wherein a chelator is coupled with attachment group A for thelabeling with radionuclides for the production of an agent fordiagnostic and therapy of benign and malignant diseases, in which theGLP-1 receptor expression plays a role.
 39. Application of peptidederivatives from exendin-4, wherein their C-terminus is modified by anamine and wherein their N-terminus binds to the GLP-1 receptor, with asequence identity of over 90% to the amino acid sequence of exendin-4:H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38  39

wherein the peptide derivatives are based on exendin-4 (1-39)A, with Abeing an attachment group comprising of one or more amino acids or itsderivatives as a signal molecule, or to bond signal molecules or tostabilize them, which is located at the C-terminus and represents anamine, wherein a chelator is coupled with attachment group A for thelabeling with radionuclides in order to determine the density of insulinproducing cells in a tissue.
 40. Application of peptide derivatives fromexendin-4, wherein their C-terminus is modified by an amine and whereintheir N-terminus binds to the GLP-1 receptor, with a sequence identityof over 90% to the amino acid sequence of exendin-4:H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38  39

wherein the peptide derivatives are based on exendin-4 (1-39)A, with Abeing an attachment group comprising of one or more amino acids or itsderivatives as a signal molecule, or to bond signal molecules or tostabilize them, which is located at the C-terminus and represents anamine, wherein a chelator is coupled with attachment group A for thelabeling with radionuclides in order to determine the expression ofGLP-1 receptors or their density.
 41. Use of an agent for diagnostic andtherapy of benign and malignant diseases, in which GLP-1 receptorexpression plays a role, wherein the agent contains labeled peptidederivatives of exendin-4, wherein their C-terminus is modified by anamine and wherein their N-terminus binds to the GLP-1 receptor, with asequence identity of over 90% to the amino acid sequence of exendin-4:H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38  39

wherein the peptide derivatives are based on exendin-4 (1-39)A, with Abeing an attachment group comprising of one or more amino acids or itsderivatives as a signal molecule, or to bond signal molecules or tostabilize them, which is located at the C-terminus and represents anamine, wherein a chelator is coupled with attachment group A for thelabeling with radionuclides.
 42. Use of an agent for diagnostic andtherapy of neuroendocrine tumors (NET), particularly insulinomas andsmall cell bronchial carcinomas, wherein the agent contains labeledpeptide derivatives from exendin-4, wherein their C-terminus is modifiedby an amine and wherein their N-terminus binds to the GLP-1 receptor,with a sequence identity of over 90% to the amino acid sequence ofexendin-4:H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38  39

wherein the peptide derivatives are based on exendin-4 (1-39)A, with Abeing an attachment group comprising of one or more amino acids or itsderivatives as a signal molecule, or to bond signal molecules or tostabilize them, which is located at the C-terminus and represents anamine, wherein a chelator is coupled with attachment group A for thelabeling with radionuclides.
 43. Use of an agent in scintigraphy, PET,SPECT, MRI, optical diagnostic, receptor-mediated chemotherapy,receptor-mediated, cytostatic or cytotoxic therapy and radiopeptidetherapy, wherein the agent contains labeled peptide derivatives ofexendin-4, wherein their C-terminus is modified by an amine and whereintheir N-terminus binds to the GLP-1 receptor, with a sequence identityof over 90% to the amino acid sequence of exendin-4:H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38  39

wherein the peptide derivatives are based on exendin-4 (1-39)A, with Abeing an attachment group comprising of one or more amino acids or itsderivatives as a signal molecule, or to bond signal molecules or tostabilize them, which is located at the C-terminus and represents anamine, wherein a chelator is coupled with attachment group A for thelabeling with radionuclides.
 44. Use of an agent for diagnostic andtherapy of benign and malignant diseases, in which GLP-1 receptorexpression plays a role, wherein the agent contains unlabeled peptidederivatives from exendin-4, wherein their C-terminus is modified by anamine and wherein their N-terminus binds to the GLP-1 receptor, with asequence identity of over 90% to the amino acid sequence of exendin-4:H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38  39

wherein the peptide derivatives are based on exendin-4 (1-39)A, with Abeing an attachment group comprising of one or more amino acids or itsderivatives as a signal molecule, or to bond signal molecules or tostabilize them, which is located at the C-terminus and represents anamine, wherein a chelator is coupled with attachment group A for thelabeling with radionuclides.
 45. Use of an agent for diagnostic andtherapy of neuroendocrine tumors (NET), particularly insulinomas andsmall cell bronchial carcinomas, wherein the agent contains unlabeledpeptide derivatives from exendin-4, wherein their C-terminus is modifiedby an amine and wherein their N-terminus binds to the GLP-1 receptor,with a sequence identity of over 90% to the amino acid sequence ofexendin-4:H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-  1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35Pro-Pro-Pro-Ser-NH₂ 36  37  38  39

wherein the peptide derivatives are based on exendin-4 (1-39)A, with Abeing an attachment group comprising of one or more amino acids or itsderivatives as a signal molecule, or to bond signal molecules or tostabilize them, which is located at the C-terminus and represents anamine, wherein a chelator is coupled with attachment group A for thelabeling with radionuclides.